Organotin trimercaptides of 2-mercaptothiazole and derivatives thereof



United States Patent ORGANOTIN TRIMERCAPTIDES OE Z-MERCAPTO- THIAZOLEAND DERIVATIVES THEREOF Eugene P. Stctl, Churchill Valley, Pa., andChris E. Best, Franklin Township, Summit County, Ohio, assiguors to TheFirestone Tire & Rubber Company, Akron, Ohio, a corporation of Ohio N0Drawing. Application September 6, 1951, Serial No. 245,418

6 Claims. (Cl. 260299) (H) TSH with organostannic acids of the formula 0R-in-OH i all under the notation given above in connection with FormulaI. Water is eliminated, with formation of the desired Compounds I.

THE SUBSTITUENT R The group R in the above formulae may be substantiallyany substituent which (a) is not too large for convenient synthesis andreactivity and (b) does not contain any groups which will interfere withthe synthesis or existence of the compound. It will be understood, ofcourse, that the atom in the group R attached to the tin atoms must be acarbon atom. In practice, a range of from 1 to 22 carbon atoms in theradical R will cover the field of radicals which will be convenientlyavailable and which w'l not be too large to be readily reactable in thesynthesis of the compounds of this invention. The radical may be, andfrom the standpoint of ready procurement and avoidance of complicationsin synthesis preferably is, a simple monovalent hydrocarbon radicalcontaining only single bonds or aromatic ring double bonds between thecarbon atoms, for instance an alkyl, cyclQalkyL'aryI, aralkyl, alkaryland like monovalent hydrocarbon radical containing from 1 to 22 carbonatoms. Likewise, this radical, in addition to simple hydrocarbonstructures, may contain various other groupings which are sufficientlylow in number, and of sufficiently non-reactive character, as not tointerfere with the synthesis of the compounds of this invention.Structures which have been found innocuous and non-interfering are interalia, aliphatic ethylenic linkages (as disthe unsaturated bonds inaromatic rings, present in numbers limited only by the size of theradical R in question i. e., from 3 to 11 such double bonds) acetyleniclinkages, ether linkages, thioether linkages, carboxylic ester linkages,fluorine atoms bonded to carbon atoms, and halogen atoms bonded to2,713,580 Patented July 19, 1955 aromatic ring carbon atoms. Of all theradicals coming within the ambit of R as above defined, the simplehydrocarbon radicals containing a total of not more than fournon-aromatic ethylenic linkages and acetylenic linkages will bepreferred, as the starting materials for these compounds will be mostreadily accessible, and less complications will be encountered in thesynthetic steps leading to the compounds; of this invention.

The radical R is brought into: the compound of this invention with theorganostannic acid (III). Suitable specific organostannic acids for thispurpose include inter alia:

Table 1 Hexadecylstannic acid Phenylstannic acid Z-thienyl stannic acidFurylstannic acid Xenylstannic acid Ethoxyethylstannic acidn-Butylstannic acid Isobutylstannic acid n-Hexylstannic acidZ-ethylhexylstannic acid Laurylstannic acid Mixed alkylstannic acidscontaining alkyl groups derived from cocoanut oil THE RADICAL Tderivatives are, inter alia,

Table II Z-mercaptobenzothiazole 4 methyl 2 mercapto-Z-mercaptothiazolene thiazole Z-mercaptothiazole 4,5dimethyl-2-mercapto- Tetrahydro 2 mercaptothiazole benzothiazole (oPhenyl) 2 mercapto- 2 mercaptonaphthothiathiazole zole THE SYNTHESIS OFTHE COMPOUND OF THIS INVENTION The compounds of this invention mayconveniently be prepared via the reaction:

under the notation given above. The reaction may be carried out bysimply fusing the reactants (II) and (III) together, with heating attemperatures in the range -200 C., it being understood that thetemperature must be high enough to fuse the reactants involved, and toevaporate the water at the prevailing pressure (subatmospheric if thetemperature is below (2.). Alternatively, the reaction may be carriedout in the presence of a liquid medium, which may be a solvent for oneor both of the reactants. Hydrocarbon solvents such as benzene, tolueneand the like are well adapted for this purpose, since they boil in arange at which they may conveniently be refluxed to entrain and removethe water produced in the reaction. Likewise, the final product (I) isgenerally soluble in these solvents, whereas usually themercaptothiazole derivative (II) and organostannic acid (III) areinsoluble, so

4-ethyl-2-mercaptothiazole that the final .re.-.

3 action mixture can be freed of unreacted material by B. Testing invinyl chloride resin filtration. The reaction is substantiallyquantitative, so Parts that no great excess of either reactant (II) or(III) need Vinyl chloride resin (copolymer of 97% vinyl chlobe employed.ride, 3% vinylidene chloride) 100 The compounds of this invention mayalso be pre- Di(2-ethylhexyl)phthalate 46 pared by the reactionTricalcium phosphate 1 (2) Silicate pigment l (IV) OlaSnR Stabrhzercompound under test 2 a A series of compositions was made up inaccordance with the foregoing schedule, using as the stabilizer each T-S-Sn-R of the organotin dimercaptides prepared as above described andtabulated below. In each case' the listed ingredients, together with thecompound under test, in

.wherein alk represents an alkali metal such as sodium the proportionlisted in the schedule were thoroughly or potassium, and the remainderof the notation is as mixed together and placed on a laboratory rollmill at given for Formula I hereinabove. The reaction may 320 F. Millingwas continued for two minutes, at the be carried out by mixing thereactants together, it dee d of Which time the gauge was set at 0.025inch and sired in the presence of an inert liquid reaction medium. thesheet removed from the mill and cooled.

The product (I) may readily be i olated by filtering Five one inchsquare specimens of each of the compoofi the insoluble alkali metalhalides. sitions prepared as above described were hung vertically in aforced-draft oven maintained at 170 C. Specimens of each of thecompositions were removed at intervals of 15, 30, 60, 90 and 120 minutesof exposure PROPERTIES AND USES OF THE COMPOUNDS OF THIS INVENTION Themercaptides of this invention, particularly when in the oven, and wererated subjectively as to color prepared from reactants containing onlysingle species and extent of deterioration by the operator, which ratofcompounds coming under formulae II, III, IV and V ings are set forthherewith in Table III opposite the above, are crystalline compoundscommonly melting at tabulation of the preparation of the compound undertemperatures in the range 1004.20" C. When prepared test. By way ofcontrast, a composition in accordance from mixed compounds, e. g. thosein which R, reprewith the above formula, but omitting any stabilizer,sents mixed radicals obtained from natural fatty glyceride showed markeddeterioration after as short a time as 15 oils or from petroleumfractions, the products naturally minutes in the oven, see the last itemin the table.

Table III Constitution of Mercaptide Product V Amt of Vinyl ResinStability Test Properties of Mercap' Color of Test Specimen AfterExposure In Oven For Run tide Used Group Attached To MercaptothiazoleProduct (partsby No. T 1n in Organostan- D U n h I n1c Acid a "1 w 15 n,30 m 60 min. 90 mm. 120 mm. Butyl mglercaptobenzolight-orfingegis- 2taint straw" light straw. stra tan light brown. 1

, mm c. cous iqui Lorol 1 do viscous liquid 2 off white pale straw do..do do 2 1 no 1.5973. Blankno stabilizer 0 tan dark tan. brown. darkbrown. dark brown. 3

1 The mixed alkyl groups derived from cocoanut oil fatty acids. 7 haveno sharp melting point. Such preparations never- From the foregoinggeneral description and detailed theless come within the ambit of thisinvention, prospecific examples, it will be evident that this inventionviding that they contain mixtures of compounds indiprovides novelmercaptide compounds useful, inter alia, vidually answering Formula Iabove. The compounds as stabilizers in vinyl chloride resins. Thecompounds are of this invention are useful, inter alia, as stabilizersin 60 based upon the cheaply and readily availableZ-mercaptoorganicmaterials, and particularly as heat stabilizers inthiazole derivatives and organostannic acids, and are resins based uponvinyl chloride. arrived at by way of relatively single syntheses.

With the foregoing general discussion in mind, there What is claimed is:I are given herewith detailed examples of the practice of 1. A compoundof the formula 7 this invention. All parts 'given are on the basis ofweight. S

EXAMPLE I A. Preparation of mercaptide T S7SHTR Organostannic acidgram-moles .017 3 S Mercaptothiazole derivative do .050 no Toluene ml100 wherein R represents a hydrocarbon radical containing A series ofmercaptides was prepared reacting from 1 to 22 carbon atoms and Trepresents a radical various organostannic acids with variousmercaptothia- Selected from the group consisting of 2-(beI1Z0thiaZ01Y1),

zole derivatives as indicated in Table I. In each case 7 Q Y iy2-(tetl'ahydrobenlQthialol' the selected organostannic acid, selectedmercaptothia- YD. -(Q-P y Y Y Y zole derivative, and toluene, in theproportions indicated -(b l y Y Y and in the above recipe, were refluxedat atmospheric prestn ph h z lynsure for three hours under a condenserprovided with A mp n of the formula a water-trap so as to divert therefluxed water-while returning the toluene to the reaction mixture. There- CHI action mixture was then cooled to room temperature, Q, \Q. Nfiltered to remove any insoluble material, and then heated S to stripoff the toluene. The residue was taken as being 0 n a a substantiallypure organotin trimercaptide of the metcaptothiazole derivative. 76 CH13. A compound of the formula 4. A compound of the formula 5. A compoundof the formula wherein R represents a hydrocarbon radical eon from 1 to22 carbon atoms.

taining 6. A compound of the formula wherein R represents ahydrocarbon-radical containing 1 from 1 to 22 carbon atoms.

References Cited in the file of this patent UNITED STATES PATENTS ScottDec. 29, 1931 Beber Sept. 2, 1947 OTHER REFERENCES

1. A COMPOUND OF THE FORMULA 